Histological Evidence of the Great Obstetrical Syndromes and Short-Term Neonatal Outcomes

Great obstetrical syndrome (GOS) represents a group of pregnancy-related diseases that result in inadequate placentation. Most GOS cases end in preterm, either spontaneously or indicatively, and the use of antenatal corticosteroids (ACS) is inevitably discussed. The placenta is an important, transient fetal-derived organ and is the embodiment of maternal or fetal well-being. However, few studies provide histological evidence of the placenta in GOS. This study aims to address these issues.

A total of 831 pregnant women were prospectively recruited. Placenta tissue was collected immediately and fixed with 4% paraformaldehyde solution for future H&E analysis. A novel checklist was devised to evaluate maternal vascular malperfusion sections on the basis of the commonly accepted Amsterdam placental workshop group consensus statement.

A total of 131 patients were classified as having GOS. Comparisons between those with and without GOS revealed significant differences, including higher levels of distal villous hypoplasia, increased syncytial knots, accelerated villous maturation, and higher total scores in GOS. We found significant negative associations between GOS and neonatal weight, neonatal height, head circumference, placental surface area, placental volume, and placenta gross examination score. GOS neonates were 1.25 times more likely to have hyperbilirubinemia. Regarding the effect of ACS, a significant reduction in birthweight, height, and head circumference was observed, along with an increased risk of hyperbilirubinemia.

This study provides histological evidence of the GOS that supports the defective deep placentation hypothesis. Our research also contributes to benefit-risk consultation in the GOS, such as in cases of PE and FGR, where a balance between fetal lung maturation and short-term neonatal outcomes is crucial.